Fuuun Ishin Dai☆Shogun Dai-Shogun - Great Revolution
In the late Edo period, Japan faced an unprecedented crisis with the arrival of black ships from overseas. However, Japan drove away the black ships thanks to Onigami, giant robots that have existed in Japan since the ancient times. The country has remained in self-imposed seclusion from foreigners ever since. The story begins in this Japan that never experienced the Meiji Restoration.
[Source: Anime News Network]